?
Categories
Account

Two blocks of masses 2 kg and 3 kg are connected by a light string over a fricti

  • 📥 Instant PDF Download
  • ♾ Lifetime Access
  • 🛡 Secure & Original Content

What’s inside this PDF?

Question: Two blocks of masses 2 kg and 3 kg are connected by a light string over a frictionless pulley. If the 3 kg block is hanging, what is the acceleration of the system?

Options:

  1. 1.2 m/s²
  2. 2 m/s²
  3. 3 m/s²
  4. 4 m/s²

Correct Answer: 1.2 m/s²

Solution:

Using Newton\'s second law, the net force is (3 kg * 9.8 m/s²) - (2 kg * a) = (2 kg + 3 kg) * a. Solving gives a = 1.2 m/s².

Two blocks of masses 2 kg and 3 kg are connected by a light string over a fricti

Practice Questions

Q1
Two blocks of masses 2 kg and 3 kg are connected by a light string over a frictionless pulley. If the 3 kg block is hanging, what is the acceleration of the system?
  1. 1.2 m/s²
  2. 2 m/s²
  3. 3 m/s²
  4. 4 m/s²

Questions & Step-by-Step Solutions

Two blocks of masses 2 kg and 3 kg are connected by a light string over a frictionless pulley. If the 3 kg block is hanging, what is the acceleration of the system?
  • Step 1: Identify the masses of the blocks. The first block has a mass of 2 kg and the second block has a mass of 3 kg.
  • Step 2: Understand that the 3 kg block is hanging and will cause the system to accelerate downwards due to gravity.
  • Step 3: Calculate the weight of the 3 kg block using the formula: weight = mass * gravity. Here, gravity is approximately 9.8 m/s². So, weight = 3 kg * 9.8 m/s² = 29.4 N.
  • Step 4: The 2 kg block will experience a force due to the tension in the string. We need to find the net force acting on the system.
  • Step 5: Write the equation for the net force. The net force is the weight of the 3 kg block minus the force due to the acceleration of the 2 kg block: (3 kg * 9.8 m/s²) - (2 kg * a).
  • Step 6: The total mass of the system is the sum of both blocks: 2 kg + 3 kg = 5 kg.
  • Step 7: According to Newton's second law, the net force is also equal to the total mass times the acceleration: (2 kg + 3 kg) * a.
  • Step 8: Set the two expressions for net force equal to each other: (3 kg * 9.8 m/s²) - (2 kg * a) = (2 kg + 3 kg) * a.
  • Step 9: Rearrange the equation to solve for acceleration 'a'. This gives: 29.4 N - 2a = 5a.
  • Step 10: Combine like terms: 29.4 N = 7a.
  • Step 11: Solve for 'a' by dividing both sides by 7: a = 29.4 N / 7 = 4.2 m/s².
  • Step 12: The final answer for the acceleration of the system is approximately 4.2 m/s².
  • Newton's Second Law – The relationship between the net force acting on an object, its mass, and its acceleration.
  • Tension in a String – Understanding how tension affects the motion of connected masses.
  • Free Body Diagrams – Visualizing forces acting on each block to analyze the system.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely
Home Practice Performance eBooks